Engineering physics — the applied-physics sub-discipline that bridges fundamental physics and engineering design, covering device physics, instrumentation, measurement science, and control systems. Foundations: (1) Semiconductor device…
engineering-physics
Shockley diode: I = I_s·(exp(q·V/k_B·T) - 1)
The Shockley ideal diode equation — the foundational I-V relation for a p-n junction: I = I_s·(exp(q·V/k_B·T) - 1), where I_s is the…
MOSFET saturation: I_D = (K/2)·(V_GS - V_T)²
The MOSFET saturation-region drain current follows the 'square-law' model: I_D = (K/2)·(V_GS - V_T)², where K = μ_n·C_ox·W/L (μ_n electron…
RC low-pass: f_3dB = 1/(2π·R·C); |H|² at ω_c = 1/2
The first-order RC low-pass filter has transfer function H(ω) = 1/(1 + j·ω·R·C), hence magnitude-squared |H(ω)|² = 1/(1 + (ω·R·C)²). The…
Shockley zero-bias: I(V=0) = 0
Sympy-exact witness of the Shockley-diode zero-bias identity. Setup: I = I_s·(exp(q·V/(T·k_B)) - 1) as a four-symbol function. Identity:…
MOSFET anchor: I_D(V_GS=V_T)=0; I_D(V_GS=2·V_T)=K·V_T²/2
Sympy-exact witness of the MOSFET-saturation anchor identities. Setup: I_D = (K/2)·(V_GS - V_T)² as a three-symbol polynomial. Identity 1…
RC low-pass cutoff: |H|²(ω=0)=1; |H|²(ω=1/RC)=1/2
Sympy-exact witness of the RC low-pass limiting magnitudes. Setup: |H(ω)|² = 1/(1 + (ω·R·C)²) as a three-symbol rational function. …